[PATCH -next] smp: Move stub from main.c into smp.h

[PATCH -next] smp: Move stub from main.c into smp.h

[Yue Zou]

Move the stubs in init/main.c for !CONFIG_SMP to smp.h
since these definitions for CONFIG_SMP are in smp.h already.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Yue Zou <zouyue3@huawei.com>
---
 include/linux/smp.h | 4 ++++
 init/main.c         | 5 -----
 2 files changed, 4 insertions(+), 5 deletions(-)

diff --git a/include/linux/smp.h b/include/linux/smp.h
index a80ab58ae3f1..bc42f6f8415a 100644
--- a/include/linux/smp.h
+++ b/include/linux/smp.h
@@ -183,6 +183,10 @@ static inline int get_boot_cpu_id(void)
 
 #else /* !SMP */
 
+static const unsigned int setup_max_cpus = NR_CPUS;
+static inline void setup_nr_cpu_ids(void) { }
+static inline void smp_prepare_cpus(unsigned int maxcpus) { }
+
 static inline void smp_send_stop(void) { }
 
 /*
diff --git a/init/main.c b/init/main.c
index 0f452ae3b20f..3c432b28c78f 100644
--- a/init/main.c
+++ b/init/main.c
@@ -602,11 +602,6 @@ static int __init rdinit_setup(char *str)
 }
 __setup("rdinit=", rdinit_setup);
 
-#ifndef CONFIG_SMP
-static const unsigned int setup_max_cpus = NR_CPUS;
-static inline void setup_nr_cpu_ids(void) { }
-static inline void smp_prepare_cpus(unsigned int maxcpus) { }
-#endif
 
 /*
  * We need to store the untouched command line for future reference.
-- 
2.25.1

Re: [PATCH -next] smp: Move stub from main.c into smp.h

[kernel test robot]

Hi Yue,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on next-20220527]

url:    https://github.com/intel-lab-lkp/linux/commits/Yue-Zou/smp-Move-stub-from-main-c-into-smp-h/20220528-185146
base:    d3fde8ff50ab265749704bd7fbcf70d35235421f
config: x86_64-randconfig-a013 (https://download.01.org/0day-ci/archive/20220528/202205282032.H8Urbl9N-lkp@intel.com/config)
compiler: gcc-11 (Debian 11.3.0-1) 11.3.0
reproduce (this is a W=1 build):
        # https://github.com/intel-lab-lkp/linux/commit/2efe286bd89edfa5448d29a5be89fd54df424c46
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Yue-Zou/smp-Move-stub-from-main-c-into-smp-h/20220528-185146
        git checkout 2efe286bd89edfa5448d29a5be89fd54df424c46
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 O=build_dir ARCH=x86_64 prepare

If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

   In file included from include/linux/lockdep.h:14,
                    from include/linux/spinlock.h:62,
                    from include/linux/mmzone.h:8,
                    from include/linux/gfp.h:6,
                    from include/linux/slab.h:15,
                    from include/linux/crypto.h:20,
                    from arch/x86/kernel/asm-offsets.c:9:
>> include/linux/smp.h:186:27: warning: 'setup_max_cpus' defined but not used [-Wunused-const-variable=]
     186 | static const unsigned int setup_max_cpus = NR_CPUS;
         |                           ^~~~~~~~~~~~~~
--
   fs/d_path.c:318:7: warning: no previous prototype for 'simple_dname' [-Wmissing-prototypes]
     318 | char *simple_dname(struct dentry *dentry, char *buffer, int buflen)
         |       ^~~~~~~~~~~~
   In file included from include/linux/lockdep.h:14,
                    from include/linux/spinlock.h:62,
                    from include/linux/wait.h:9,
                    from include/linux/wait_bit.h:8,
                    from include/linux/fs.h:6,
                    from include/uapi/linux/aio_abi.h:31,
                    from include/linux/syscalls.h:77,
                    from fs/d_path.c:2:
>> include/linux/smp.h:186:27: warning: 'setup_max_cpus' defined but not used [-Wunused-const-variable=]
     186 | static const unsigned int setup_max_cpus = NR_CPUS;
         |                           ^~~~~~~~~~~~~~
--
   fs/io_uring.c: In function '__io_submit_flush_completions':
   fs/io_uring.c:3152:40: warning: variable 'prev' set but not used [-Wunused-but-set-variable]
    3152 |         struct io_wq_work_node *node, *prev;
         |                                        ^~~~
   In file included from include/linux/lockdep.h:14,
                    from include/linux/spinlock.h:62,
                    from include/linux/wait.h:9,
                    from include/linux/wait_bit.h:8,
                    from include/linux/fs.h:6,
                    from include/uapi/linux/aio_abi.h:31,
                    from include/linux/syscalls.h:77,
                    from fs/io_uring.c:45:
   At top level:
>> include/linux/smp.h:186:27: warning: 'setup_max_cpus' defined but not used [-Wunused-const-variable=]
     186 | static const unsigned int setup_max_cpus = NR_CPUS;
         |                           ^~~~~~~~~~~~~~
--
   In file included from include/linux/lockdep.h:14,
                    from include/linux/spinlock.h:62,
                    from include/linux/mmzone.h:8,
                    from include/linux/gfp.h:6,
                    from include/linux/slab.h:15,
                    from include/linux/crypto.h:20,
                    from arch/x86/kernel/asm-offsets.c:9:
>> include/linux/smp.h:186:27: warning: 'setup_max_cpus' defined but not used [-Wunused-const-variable=]
     186 | static const unsigned int setup_max_cpus = NR_CPUS;
         |                           ^~~~~~~~~~~~~~


vim +/setup_max_cpus +186 include/linux/smp.h

   185	
 > 186	static const unsigned int setup_max_cpus = NR_CPUS;
   187	static inline void setup_nr_cpu_ids(void) { }
   188	static inline void smp_prepare_cpus(unsigned int maxcpus) { }
   189	

-- 
0-DAY CI Kernel Test Service
https://01.org/lkp

Re: [PATCH -next] smp: Move stub from main.c into smp.h

[kernel test robot]

Hi Yue,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on next-20220527]

url:    https://github.com/intel-lab-lkp/linux/commits/Yue-Zou/smp-Move-stub-from-main-c-into-smp-h/20220528-185146
base:    d3fde8ff50ab265749704bd7fbcf70d35235421f
config: arc-randconfig-r043-20220526 (https://download.01.org/0day-ci/archive/20220528/202205282043.QMZuMrL0-lkp@intel.com/config)
compiler: arc-elf-gcc (GCC) 11.3.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/intel-lab-lkp/linux/commit/2efe286bd89edfa5448d29a5be89fd54df424c46
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Yue-Zou/smp-Move-stub-from-main-c-into-smp-h/20220528-185146
        git checkout 2efe286bd89edfa5448d29a5be89fd54df424c46
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.3.0 make.cross W=1 O=build_dir ARCH=arc SHELL=/bin/bash lib/

If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

   In file included from include/linux/lockdep.h:14,
                    from include/linux/spinlock.h:62,
                    from include/linux/kref.h:16,
                    from include/linux/mm_types.h:8,
                    from include/linux/buildid.h:5,
                    from include/linux/module.h:14,
                    from lib/test_bitops.c:9:
>> include/linux/smp.h:186:27: error: 'setup_max_cpus' defined but not used [-Werror=unused-const-variable=]
     186 | static const unsigned int setup_max_cpus = NR_CPUS;
         |                           ^~~~~~~~~~~~~~
   cc1: all warnings being treated as errors


vim +/setup_max_cpus +186 include/linux/smp.h

   185	
 > 186	static const unsigned int setup_max_cpus = NR_CPUS;
   187	static inline void setup_nr_cpu_ids(void) { }
   188	static inline void smp_prepare_cpus(unsigned int maxcpus) { }
   189	

-- 
0-DAY CI Kernel Test Service
https://01.org/lkp

Re: [PATCH -next] smp: Move stub from main.c into smp.h

[Thomas Gleixner]

On Sat, May 28 2022 at 11:11, Yue Zou wrote:
>  #else /* !SMP */
>  
> +static const unsigned int setup_max_cpus = NR_CPUS;

This will cause a 'defined but not used warning' for all files which
include smp.h, except for init/main.c

Thanks,

        tglx